P53 expression between 13-27 weeks old human male fetus gonads.

P53 is a tumor suppressor gene and a critical component of cellular mechanisms that respond to genotoxic stresses. During normal fetal development, some of these cells lose their genomic stability because of intensive cell proliferation. They arrest cell cycle progression and repair genomic stability by p53 induction or die via apoptosis. If p53 is overexpressed, some structures may have different abnormalities. This study was conducted to investigate normal p53 expression in human male gonads during second trimester. Twenty one normal human male fetuses' testes in 2nd trimester were processed and immunohistochemistry was applied. The spermatogonia with nuclear and perinuclear staining, were accepted as p53 (+). The number of p53 (+) spermatogonia was counted in randomly 10 different seminiferous tubules. The results suggest that p53 expression in gonads of human male fetuses significantly increases in the 20th week.